1. Field
Example embodiments relate to a maskless exposure apparatus to efficiently process frame data of a Digital Micro-mirror Device (DMD) and a frame data processing method thereof.
2. Description of the Related Art
In general, in a method of forming a pattern on a substrate included in a flat panel display such as a liquid crystal display or a plasma display panel, the substrate is coated with a pattern material, the pattern material is selectively exposed using a photomask, a pattern material portion having modified chemical properties or the other portion is selectively removed, thereby forming the pattern.
As the size of a substrate is increased and a pattern formed on an exposed surface becomes more precise, manufacturing costs of a photomask are increased. However, since a maskless exposure apparatus does not use a photomask, costs may be reduced.
A maskless exposure apparatus forms a pattern by irradiating a light beam onto a substrate with pattern information composed of an electrical signal using an electronic device. Representative examples of the electronic device include a Digital Micro-mirror Device (DMD). In a DMD, a plurality of micro mirrors send light beams having a predetermined/desired angle of incidence at a desired angle and send the other light beams at another angle so as to form a pattern on the exposed surface using only the necessary/required light beams.
In a maskless exposure apparatus using a DMD, when a stage which moves a substrate is scanned at a constant speed in an exposure direction, a pattern image (a virtual mask in maskless exposure) to be exposed at a constant interval is compared with pixel positions of the DMD, thereby forming a frame. That is, when a pixel of the DMD overlaps an exposure pattern, a micro mirror corresponding to that pixel is set to an ON state and, when a pixel of the DMD does not overlap an exposure pattern, a micro mirror corresponding to that pixel is set to an OFF state. Thus, all pixels (for example, 1024×768 pixels) of one frame are set to the ON or OFF state so as to generate frame data.
In order to expose a 3 μm line and space pattern in consideration of a takt time of an exposure apparatus, frame data needs to be generated at a speed of 50,000 frame/sec. Therefore, a high data processing speed of 40 Gbps is required.
In large-area exposure, a glass state may be changed according to layers of a substrate. Therefore, if frame data correction is demanded upon exposure, the demand needs to be immediately satisfied.
Conventionally, an offline method of generating frame data in advance, transmitting the frame data to a DMD and performing exposure was used. However, in the conventional offline method, it may be difficult to immediately correct frame data. In addition, a correction method may become complicated.